In the evolution of data processing systems, much of the functionality which previously had been performed by hardware system components is now being constructed utilizing software programming instead. Such an approach disfavors proprietary hardware architectures and encourages open system architectures on which a multitude of software algorithms can be executed on a common hardware architecture. As a result, software programs or applications have become more powerful and increasingly complex. Unfortunately, numerous difficulties arise in the development and maintenance of such software applications. Traditional applications have become so large and complex that even minor changes may take several weeks or months to implement. Accordingly, the trend in both software development and program language development is towards more modular, self-contained software designs.
One of the major developments in the field of software design has been the emergence of object-oriented technology. As explained in greater detail hereinafter, object-oriented technology enables the analysis, design and implementation of software systems with intelligent, autonomous agents called objects. Such objects facilitate the design of modular software which more closely mimics the physical or logical entities within the real world.
Despite the emergence of object-oriented technology most end-users have been typically unable to directly utilize the efficient, more modular design of an application, even if the application has been designed using object-oriented technology. For example, users of applets, i.e., small applications such as spreadsheets and file viewers, typically wish to customize such applications for their own preferred tasks and to allow such applications to interact with one another to form larger customized applications without having to redesign or make extensive modifications to such applications. Further, even if such applications were modifiable, their inherent value is often directly related to the ability to distribute such customized applications with accompanying data in a manner which is both efficient and respects the intellectual property rights of the authors. Accordingly, a need exists for a system of intelligent, self-contained software modules which may be used to construct larger applications in a modular fashion. Further, a need exists for a technique in which software applications may be modified as desired by an end-user in the manner which is both simplified and efficient.
A further need exists for a technique in which such modifications to standard applications may be distributed and used in an efficient manner. In addition, a need exists for a technique in which use and distribution of such customized application may be performed only by those who are properly authorized by the software licensor.